让php gd库支持bmp图片处理的两个函数

php的gd2库是不支持bmp的下面是从网上收集的两个函数可以支持bmp图片处理已经 测试过可以使用

/**
 * BMP 创建函数
 * @author simon
 * @param string $filename path of bmp file
 * @example who use,who knows
 * @return resource of GD
 */
function imagecreatefrombmp( $filename ){
    if ( !$f1 = fopen( $filename, "rb" ) )
        return FALSE;
     
    $FILE = unpack( "vfile_type/Vfile_size/Vreserved/Vbitmap_offset", fread( $f1, 14 ) );
    if ( $FILE['file_type'] != 19778 )
        return FALSE;
     
    $BMP = unpack( 'Vheader_size/Vwidth/Vheight/vplanes/vbits_per_pixel' . '/Vcompression/Vsize_bitmap/Vhoriz_resolution' . '/Vvert_resolution/Vcolors_used/Vcolors_important', fread( $f1, 40 ) );
    $BMP['colors'] = pow( 2, $BMP['bits_per_pixel'] );
    if ( $BMP['size_bitmap'] == 0 )
        $BMP['size_bitmap'] = $FILE['file_size'] - $FILE['bitmap_offset'];
    $BMP['bytes_per_pixel'] = $BMP['bits_per_pixel'] / 8;
    $BMP['bytes_per_pixel2'] = ceil( $BMP['bytes_per_pixel'] );
    $BMP['decal'] = ($BMP['width'] * $BMP['bytes_per_pixel'] / 4);
    $BMP['decal'] -= floor( $BMP['width'] * $BMP['bytes_per_pixel'] / 4 );
    $BMP['decal'] = 4 - (4 * $BMP['decal']);
    if ( $BMP['decal'] == 4 )
        $BMP['decal'] = 0;
     
    $PALETTE = array();
    if ( $BMP['colors'] < 16777216 ){
        $PALETTE = unpack( 'V' . $BMP['colors'], fread( $f1, $BMP['colors'] * 4 ) );
    }
     
    $IMG = fread( $f1, $BMP['size_bitmap'] );
    $VIDE = chr( 0 );
     
    $res = imagecreatetruecolor( $BMP['width'], $BMP['height'] );
    $P = 0;
    $Y = $BMP['height'] - 1;
    while( $Y >= 0 ){
        $X = 0;
        while( $X < $BMP['width'] ){
            if ( $BMP['bits_per_pixel'] == 32 ){
                $COLOR = unpack( "V", substr( $IMG, $P, 3 ) );
                $B = ord(substr($IMG, $P,1));
                $G = ord(substr($IMG, $P+1,1));
                $R = ord(substr($IMG, $P+2,1));
                $color = imagecolorexact( $res, $R, $G, $B );
                if ( $color == -1 )
                    $color = imagecolorallocate( $res, $R, $G, $B );
                $COLOR[0] = $R*256*256+$G*256+$B;
                $COLOR[1] = $color;
            }elseif ( $BMP['bits_per_pixel'] == 24 )
                $COLOR = unpack( "V", substr( $IMG, $P, 3 ) . $VIDE );
            elseif ( $BMP['bits_per_pixel'] == 16 ){
                $COLOR = unpack( "n", substr( $IMG, $P, 2 ) );
                $COLOR[1] = $PALETTE[$COLOR[1] + 1];
            }elseif ( $BMP['bits_per_pixel'] == 8 ){
                $COLOR = unpack( "n", $VIDE . substr( $IMG, $P, 1 ) );
                $COLOR[1] = $PALETTE[$COLOR[1] + 1];
            }elseif ( $BMP['bits_per_pixel'] == 4 ){
                $COLOR = unpack( "n", $VIDE . substr( $IMG, floor( $P ), 1 ) );
                if ( ($P * 2) % 2 == 0 )
                    $COLOR[1] = ($COLOR[1] >> 4);
                else
                    $COLOR[1] = ($COLOR[1] & 0x0F);
                $COLOR[1] = $PALETTE[$COLOR[1] + 1];
            }elseif ( $BMP['bits_per_pixel'] == 1 ){
                $COLOR = unpack( "n", $VIDE . substr( $IMG, floor( $P ), 1 ) );
                if ( ($P * 8) % 8 == 0 )
                    $COLOR[1] = $COLOR[1] >> 7;
                elseif ( ($P * 8) % 8 == 1 )
                    $COLOR[1] = ($COLOR[1] & 0x40) >> 6;
                elseif ( ($P * 8) % 8 == 2 )
                    $COLOR[1] = ($COLOR[1] & 0x20) >> 5;
                elseif ( ($P * 8) % 8 == 3 )
                    $COLOR[1] = ($COLOR[1] & 0x10) >> 4;
                elseif ( ($P * 8) % 8 == 4 )
                    $COLOR[1] = ($COLOR[1] & 0x8) >> 3;
                elseif ( ($P * 8) % 8 == 5 )
                    $COLOR[1] = ($COLOR[1] & 0x4) >> 2;
                elseif ( ($P * 8) % 8 == 6 )
                    $COLOR[1] = ($COLOR[1] & 0x2) >> 1;
                elseif ( ($P * 8) % 8 == 7 )
                    $COLOR[1] = ($COLOR[1] & 0x1);
                $COLOR[1] = $PALETTE[$COLOR[1] + 1];
            }else
                return FALSE;
            imagesetpixel( $res, $X, $Y, $COLOR[1] );
            $X++;
            $P += $BMP['bytes_per_pixel'];
        }
        $Y--;
        $P += $BMP['decal'];
    }
    fclose( $f1 );
     
    return $res;
}
/** 
* 创建bmp格式图片 
* 
* @author: legend(legendsky@hotmail.com) 
* @link: http://www.ugia.cn/?p=96 
* @description: create Bitmap-File with GD library 
* @version: 0.1 
* 
* @param resource $im          图像资源 
* @param string   $filename    如果要另存为文件，请指定文件名，为空则直接在浏览器输出 
* @param integer  $bit         图像质量(1、4、8、16、24、32位) 
* @param integer  $compression 压缩方式，0为不压缩，1使用RLE8压缩算法进行压缩 
* 
* @return integer 
*/ 
function imagebmp(&$im, $filename = '', $bit = 8, $compression = 0) 
{ 
    if (!in_array($bit, array(1, 4, 8, 16, 24, 32))) 
    { 
        $bit = 8; 
    } 
    else if ($bit == 32) // todo:32 bit 
    { 
        $bit = 24; 
    } 
  
    $bits = pow(2, $bit); 
    
    // 调整调色板 
    imagetruecolortopalette($im, true, $bits); 
    $width  = imagesx($im); 
    $height = imagesy($im); 
    $colors_num = imagecolorstotal($im); 
    
    if ($bit <= 8) 
    { 
        // 颜色索引 
        $rgb_quad = ''; 
        for ($i = 0; $i < $colors_num; $i ++) 
        { 
            $colors = imagecolorsforindex($im, $i); 
            $rgb_quad .= chr($colors['blue']) . chr($colors['green']) . chr($colors['red']) . "\0"; 
        } 
        
        // 位图数据 
        $bmp_data = ''; 
  
        // 非压缩 
        if ($compression == 0 || $bit < 8) 
        { 
            if (!in_array($bit, array(1, 4, 8))) 
            { 
                $bit = 8; 
            } 
  
            $compression = 0; 
            
            // 每行字节数必须为4的倍数，补齐。 
            $extra = ''; 
            $padding = 4 - ceil($width / (8 / $bit)) % 4; 
            if ($padding % 4 != 0) 
            { 
                $extra = str_repeat("\0", $padding); 
            } 
            
            for ($j = $height - 1; $j >= 0; $j --) 
            { 
                $i = 0; 
                while ($i < $width) 
                { 
                    $bin = 0; 
                    $limit = $width - $i < 8 / $bit ? (8 / $bit - $width + $i) * $bit : 0; 
  
                    for ($k = 8 - $bit; $k >= $limit; $k -= $bit) 
                    { 
                        $index = imagecolorat($im, $i, $j); 
                        $bin |= $index << $k; 
                        $i ++; 
                    } 
  
                    $bmp_data .= chr($bin); 
                } 
                
                $bmp_data .= $extra; 
            } 
        } 
        // RLE8 压缩 
        else if ($compression == 1 && $bit == 8) 
        { 
            for ($j = $height - 1; $j >= 0; $j --) 
            { 
                $last_index = "\0"; 
                $same_num   = 0; 
                for ($i = 0; $i <= $width; $i ++) 
                { 
                    $index = imagecolorat($im, $i, $j); 
                    if ($index !== $last_index || $same_num > 255) 
                    { 
                        if ($same_num != 0) 
                        { 
                            $bmp_data .= chr($same_num) . chr($last_index); 
                        } 
  
                        $last_index = $index; 
                        $same_num = 1; 
                    } 
                    else 
                    { 
                        $same_num ++; 
                    } 
                } 
  
                $bmp_data .= "\0\0"; 
            } 
            
            $bmp_data .= "\0\1"; 
        } 
  
        $size_quad = strlen($rgb_quad); 
        $size_data = strlen($bmp_data); 
    } 
    else 
    { 
        // 每行字节数必须为4的倍数，补齐。 
        $extra = ''; 
        $padding = 4 - ($width * ($bit / 8)) % 4; 
        if ($padding % 4 != 0) 
        { 
            $extra = str_repeat("\0", $padding); 
        } 
  
        // 位图数据 
        $bmp_data = ''; 
  
        for ($j = $height - 1; $j >= 0; $j --) 
        { 
            for ($i = 0; $i < $width; $i ++) 
            { 
                $index  = imagecolorat($im, $i, $j); 
                $colors = imagecolorsforindex($im, $index); 
                
                if ($bit == 16) 
                { 
                    $bin = 0 << $bit; 
  
                    $bin |= ($colors['red'] >> 3) << 10; 
                    $bin |= ($colors['green'] >> 3) << 5; 
                    $bin |= $colors['blue'] >> 3; 
  
                    $bmp_data .= pack("v", $bin); 
                } 
                else 
                { 
                    $bmp_data .= pack("c*", $colors['blue'], $colors['green'], $colors['red']); 
                } 
                
                // todo: 32bit; 
            } 
  
            $bmp_data .= $extra; 
        } 
  
        $size_quad = 0; 
        $size_data = strlen($bmp_data); 
        $colors_num = 0; 
    } 
  
    // 位图文件头 
    $file_header = "BM" . pack("V3", 54 + $size_quad + $size_data, 0, 54 + $size_quad); 
  
    // 位图信息头 
    $info_header = pack("V3v2V*", 0x28, $width, $height, 1, $bit, $compression, $size_data, 0, 0, $colors_num, 0); 
    
    // 写入文件 
    if ($filename != '') 
    { 
        $fp = fopen("test.bmp", "wb"); 
  
        fwrite($fp, $file_header); 
        fwrite($fp, $info_header); 
        fwrite($fp, $rgb_quad); 
        fwrite($fp, $bmp_data); 
        fclose($fp); 
  
        return 1; 
    } 
    
    // 浏览器输出 
    header("Content-Type: image/bmp"); 
    echo $file_header . $info_header; 
    echo $rgb_quad; 
    echo $bmp_data; 
    
    return 1; 
}